Jonathan C Day <j.c.day at larc.nasa.gov> wrote:
> What's the current state of play, with regards High Availability
> software for Linux? (Yes, I've read the HOWTO, but there's no
> indication as to whether anyone's continued the HA work on it. Nor
> could I see any links to existing HA software, either there or the
> usual Linux sites. Nor was there much help from a web search.)
I have a piece of software written for Linux-HA which I announced back
in March, and due to my schedule and my corporation's bureaucracy,
hasn't yet been blessed for release (it will be GPL). However, I've
recently resubmitted it into the corporate gauntlet and hope to be able
to release it within a month.
Now, having said that: What *is* it?
It's a shot at a Linux heartbeat module. This first release will run
over serial ports, where you arrange your cluster in a ring topology.
Similar to FDDI, etc. Very good for small clusters, less suitable for
large ones. However, the architecture is suitable for plugging in other
kinds of heartbeat modules into.
Kinds that come to mind include:
- IP broadcast
- IP multicast
- IrDa
- SCSI
But what does it DO?
Well, it beats :-), and it will run a script when a new machine
which wasn't alive comes online
It will run a script when a machine which was alive stops
beating...
It provides an administrative communication infrastructure for
the cluster which is able to do more than a simple
"The OS and heartbeat code are alive" type of
communication (though that's all it does now).
It's basic, simple and somewhat flexible. It's a start.
-- Alan Robertson
alanr at bell-labs.com